1. Field of the Invention
The present invention relates to video system, and more specifically, to a method and an apparatus for de-interlacing video data.
2. Description of the Prior Art
In conventional interlaced scanning, a frame is composed of two fields, which are an odd field composed of odd scan lines, and an even field composed of even scan lines.
In progressive scanning (non-interlaced scanning), an odd field and an even field are combined into one frame, and then the frame is scanned at double horizontal scan frequency in sequence, so that the quality of the image (frame) is improved.
Before combining two fields into one frame, it is necessary to detect the relationship between each field in the video data. This means it is necessary to detect whether the video data is a film mode, for example, and whether the video data is 3-2 pull down or 2-2 pull down. Then, the video data is appropriately de-interlaced according to result of the film mode detection. According to the prior art, the operation of de-interlacing is simply implemented with operations of intra-field interpolation, inter-field interpolation or motion-adaptive process, like the methods disclosed in U.S. Pat. No. 6,577,345 and U.S. Pat. No. 6,512,550.
However, it is an important task to decrease the errors that appear when determining the pixel values, in order to enhance the quality of de-interlaced images (frames) or lower the costs on the related hardware.